Question

In a tennis match, a player wins a point by hitting the ballsharply
to the ground on the opponent's side of the net.
A) if the ball bounces upward from the ground with a speed of 16m/s
and is caught by a afan with a speed of 12 m/s, how high abovethe
court is the fan? Ignore air resistance.
B) Explain why it is not necessary to know the mass of
theball.